US2467933A - Machine for making artificial ice products - Google Patents

Description

MAcHmE FOR MAKING ARTIFI'CIAI..l ICE PRODUCTS. Filed Jan. 7, 1941`v 4 sheds-sheet' 1 A. Gaul-1N April y19 1949.

April 19, 1949. A. GRUHN .IMACHINE FOR MAKING ARTIFICIAL ICE PRODUCTS 4 Sheets-Sheet 2 Filed Jan. 7, 1941 lill l Il!! QQ mv April19,.1949.. l A'. GuHN 2,467,933

MACHINE FOR MAKING ARTIFICIAL ICE IRODUCTS Filed Jan. 7, 1941 4 Sheets-Sheet 5,

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' .26 'y' I 15 5@ 1 l Patented Apr. 19,

MaouiNE FOR MAKING ARTIFICIAL ICE PRODUCTS Axel Grulin', Skaade Bakker, near Hojbierg, Denmark; vested in the Attorney General of the United States Appncaun January 7. 1941, Serial No. 373,486 In DenmarkMa'rch 9, 1940 Section 3, Public Law' 690, August 8, 1946 Patent expires March 9, 1960 1'1 claims.

The present invention relates to methods` and machines for making a new artificial ice product to be used primarily, but not exclusively for 'cooling purposes.

It is previously known to continuously produce ice on the cold surface of a rotatable thin-walled elastic freezing drum submerged in a water bath,

from which the congealed material is removed by a violent breaking action forming shell-ice.

Furthermore it is known to supply a large exc/ess of liquid to the external surface or the internal surface of a rotating or stationary freezing drum or similar body to produce slush-ice which is scraped olf and swept away with the liquid or dropped upon a screen to drain off some of the excess liquid.

However, shell-ice is not satisfactory for the ice-packing of various goods because the sharp edges may injure the goods. Thus for instance fish are damaged when packing fresh fish with such ice. Slush-ice is wet and plastic, and even if in some cases it is bricketted by a comparatively expensive process its rangeof utility is much restricted. Moreover, slush-ice is unsatisfactory as its cooling power is reduced due to its Water content.

The present invention has for its object to produce an artificial ice product of a special character more suitable for various uses. This is accomplished by a new method wherein a liquid to be -congealed is supplied to a freezing surface and the ice formed thereon is removed in a nely divided state. The amount of liquid delivered per unit of time to the freezing surface, the temperature of the freezing surface and the interval of time `from the supplying of the liquid until the removal of the ice being so adjusted relative to each other as to form hard. dry ice which in this state is removed by consecutive lcutting actions, such as by means of a powerful milling cutter, lto form thin cuttings or chips. These small cuttings look like scales of a fish, large flakes of snow or may even' be smaller.

With regard to the dierence Abetween the freezing point of the liquid in question and the temperature of the freezing surface this depends upon various factors, such as the nature, the actual temperature and the freezing point of the very hard, `so that bymeans of a powerfull milling cutter an ice product of the desired character can be formed. However, by way of example in congealing fresh water the temperature of the freezing surface as a rule should not be higher y than -8- to 10 C., preferably between -15 and '-20 C., depending upon' the designed capacity of the ice making machine.

The artificial ice produced according to the invention has the character of frost-snow with large, thin, scale-like crystals or finely divided ice, dry and without sharp edges that could hurt the goods with which the ice comes into contact. This new artificial ice is much more lively and more 'easily movable than the known ice products referred to above. It can be better distributed over the goods, such as milk bottles, vegetables,

flowers, etc. When used for cooling mixtures the 'v necessary, salt can more easily be distributed uniformly throughout the mass of ice.

'Ihe invention can be applied not only to the freezing of pure water, but also to aqueous solutions ofvarious salts, such as eutectic solutions for producing eutectic ice and liquids containing antiseptic or other substances assisting in keeping food articles fresh when cooled with such ice. Besides the present method can be used for congealing milk or other fluids which must befrozen in such a way, i. e. very rapid, so that the mateliquid supplied, the period of time between the rial during the freezing process is. not divided into its various components.

In the case of the freezing surface forming the external surface of a rotatable cooling drum the latter may be partlyisubmerged into a bath of the liquid to be congealed, or the liquid may be delivered to the freezing surface through nozzles, atomizers, perforated or finely slotted tubes or in any appropriate manner permitting a regulation of the amount of liquid delivered to the freezing surface per unit of time.

A further object of the invention is to provide a machine for carrying out the method having one or more revolvable milling cutters capable of cutting the hard and dry ice formed on the freezing surface into thin chips or cuttings. The milling cutteror cutters preferably are associated withA heating means serving to maintain the same at a temperature equal to or above the freezing point of the liquid in order that the ice particles may readily leave the cutter as otherwise it would be clogged and its capacity reduced with consequent stopping or damage to the machine; For this purpose the milling cutter may be formed with a cavity through which the liquid to be congealed is passed whereby the liquid is simultaneously precooled. Alternatively as heating medium may befused the comparatively' warm liquid refrigerant cfa compression refrigerating plant cooperating with the ice making machine v for cooling its freezing surface. j

I'he character of the ice product may be varied within certainI limits by controlling the speed of rotation of the milling cutter, by changing its l direction of rotation relative to the motion ofthe freezing surface or by using milling cutters of various constructions. Thus a cylindrical milling cutter with straight or spiral grooves will give scale-like ice particles, whereas a cutter having cutting teeth arranged as one or more threads..

will make a more finely ldivided product. The milling-cutter is so adjusted as to leave a thin ice layer on the freezing surface, thereby protecting the latter.

The freezing surface may be the external or internal circumferential surface of a rotatable or stationary body of revolution.' for instance similar to the well known cooling drums, or it may be plane. Ivn such case the freezing surface is stationary whereas the liquid supplying' Fig. 2 is a longitudinal section on a larger scale of one end of the hollow shaft of the freezing drum with associated parts,

Fig. 3 is a longitudinal vertical section of the same machine along the line IIII1I of Fig. 1,

Fig. 4 is a longitudinal section on a larger scale of one end of the hollow shaft of the milling cutter of the machine,

Fig. 5 is a vertical cross-section of the upper part 'of the machine taken on the section line V-V of Fig. 1-,

Fig. 6 is a side elevation of one upper corner of the machine seen from the right side of Fig. 1,

Fig. 7 shows somewhat diagrammatically an elevation of a second embodiment of the ice making machine,

Fig. 8 shows a top view of the same, and

Fig. 9 shows aidiagrammatic view of the system with the arrangement for heating the cutter.

Figs. 1-6 show one form of an ice making machine wherein the freezing surface I is the external cylindrical surface of a rotatable doublewalled drum consisting of an outer shell |a and an inner shell |b both carried by hollow spokes |c and I@l on a hollow shaft journailed in bearings 2 and 3. Between the two co-axial cylindrical shells I and Ib a narrow annular cooling chamber if is formed.

The bearings 2 and 3 are mounted on a rigid metal frame 4 carried by the top wall 5 of a large ,and long wooden/tank 5 adapted to receive the lscale-ice produced. 'Ihe bottom wall I of the shaft I'f of the freezing drum a gear wheel I0 is secured which meshes with a pinion on a shaft I2. The shaft I2 is driven by the belts I3 and Il and pulleys I5, I8, l1. and I8, Figs. 1 and 6, from an electric motor I! .mounted on the top Iwan 5 of the tank s. The freezing drum is rotated thereby comparatively slowly in the direction of the arrow A in Fig. 3.

length equal to that of the freezing drum, and

its axis of rotation 'as shown in Fig. 3 is slightly above the level of the shaft of the drum. The hollow shaft 2|) of the milling cutter is journalled inV bearings carried by brackets 20, Figs. 3 and 5, which are rigidly secured to the metal frame 4V.

The liquid to be congealed is supplied from the bottom of a container 22 through a strainer23, Fig. 1, a pipe 24 and other connections described below to the right hand end of a jet pipe or nozzle member 25 placed parallel to the axis of the freezing drum and slightly above the milling cutter 2| as shown in Fig. 3. The jet pipe or nozzle member 25 spreads the liquid in fine jets or sprays over the entire length ofthe freezing surface I.

In operation a refrigerating medium, such as liquid ammonia, is supplied to the right hand end, Fig. l, of the hollow shaft Ie of the freezing drum, from which it flows through the hollow spokes |c to the narrow cooling chamber If where the liquid is evaporated thereby cooling the drum. The refrigerant gas flows through the hollow spokes Id at the opposite end of the freezing drum to a refrigerant gas pipe 26 preferably continued as a coolingl coll 21 which is suspended from the top wall 5 of the wooden tank 6 as clearly shown in Figs. 3 and 5to prevent thawing of the scaleice accumulated in the tank.

When the freezing drum is rotated and liquid is spread over the same the liquid will be congealed and form a film `or layer of hard dry ice of such thickness that part thereof can be removed by the rapidly'revolving cutter 2| which in the present case is assumed to have straight parallel cutting edges. As the milling cutter is angularly spaced more than 300from the jet pipe or nozzle member 25 in the direction of rotation of the drum and the liquid is supplied in a moderate quantity only the liquid gets sufficient time to be frozen uniformly throughout to form a very hard, dry layer of ice. Another factor important in obtaining this result is that the particular construction of the freezing drum en-' sures that all of the refrigerating medium is forcibly passed through the narrow annular cooling chamber If and thereby kept in close contact with the outer shell I of the drum. The'thin ice scale or chips cut off by milling cutter 2| are thrown into the wooden tank 6 where they are collected. The dry ice appearing as frost snow may be removed through a door not shown, preferably placed at the left end of the wooden tank,`Fig. 3, in one of the longitudinal walls thereof. The cooling coil 21 prevents thawing of the accumulated ice. 1

The machine is provided with aconveying device to distribute the ice throughout the entire length of the wooden tank. At each end of the tank near the top thereof there is rotatably mounted shafts 28 and 29. The shaft 28 is driven by a belt 30 and pulleys 3| and 32 from the shaft belts are interconnected by a series of'transversely arranged sticks or bars 3l which travel in the direction of the arrows VC shown in Figs. 3 and 5.

The ends of the stick slide on and are supportedv by upper and lower stationary guide rails I3 and 31 which have downwardly curved ends as shown.

When the heap of scale ice accumulated -in the wooden tank below the milling cutter becomes too high the top of the heap is moved away by the sticks 35 towards the left end of the` tank Fig. 3 uniformly` distributing the ice over the bottom thereof.

Some further details of the machine will now be explained with reference to Figs. 2 and 4. i

Fig. 2 shows part of the hollow shaft 1 of the freezing drum at the refrigerant inlet and outlet end thereof. A stationary tube 33 rigidly secured to the refrigerant gas pipe 26 projects into the open end of the rotating shaft le and is sealed thereagainst by astufllng box 23 of any standard type. The inner end of the tube 38 is screwed onto a plug 40 sealed against the inner cylindrical wall of the shaft I whereas the outer end the liquid is precooled before being'sprayed onto the freezing surface I but the shaft and the `milling cutter 2l are heated and thus maintained at a temperature equal to or slightly higher than the freezing point of the liquid so that clogging of the cutting edges of the milling cutter by ice particles is prevented and the continued effective operation of the cutter ensured,

In the embodiment of the machine described the ice is simultaneously removed throughout the entire width of the freezing surface by means of the milling cutter 2|. However, a short revolving millingcutter may be used which is reciprocated. Also, particularly in the case oflarger drums, a plurality of milling cutters may be used. As above stated the character of the removed ice may be varied by altering the construction or the mode of operation of the cutter or cutters.

As a dry thin lm of ice is left on the rotating freezing surface after passing the milling cutters it may be advantageous to even out the liquid supplied to the freezing surface by means of a smooth roller or strip, for instance of rubber, not

shown, bearing against the drum shortly beyond of the tube is connected to a plug 4I connectedv l with a liquid ammonia supply .pipe 42, Fig. 1.

The plug 4I is also connected to a thin pipe 43 which passes through the interior of the tube 38 and is connected at its other end in the plug 40. Through this pipe 43 the liquid refrigerant flows into the hollow middle portion of the shaft le, whereas the refrigerant gas coming from the hollow spokes Ifl flows through apertures 44 into the tube member 38 and thence away through the pipe 26 as indicated by the arrows.

For sealing purposes oil is supplied to the interior of the stufng box 39 through a small pipe 45 from an oil receptacle 46. Through a vertical pipe 41 refrigerant gas has access to a space above the oil level in the receptacle 45 whereby an oil pressure is established in the stuffing box which is slightly higher than that of the refrigerant gas to prevent escape of the same to the outer atmosphere. i

One end of the hollow shaft 20 of the milling cutter 2| is closed while the other end shown in Fig. 4 is open and supported in a housing 48 having a ball bearing 49 with lock nuts 21|IJ for this end of the shaft. The opposite end of the shaft is journalled in a similar ball bearing. A stationary tube 50 provided with two hose spigots 5l and 52 and a draining cock 53 is sealed against the end of the rapidly revolving shaft 20 by a stuffing box 54. The liquid to be congealed flows from the pipe` 24, Fig. lythrough a cock 55 and a rubber hose 55, Fig. 6, to the central spigot 52 of the tube 50 in Fig. 4, wherefrom the liquid is conducted through a small pipe 52 to the opposite end of the cutter shaft 20 where the liquid reverses and returns through the hollow shaft 2li and the tube 50 to the laterally disposed spigot 5I. FromA this spigot the liquid through a sec. ond rubber hose not shown is passed to the right han'd end of the jet pipe 25, Fig. l, as indicated' above.l The opposite end of this ljet pipe is vented by means of a rubber hose 56 and a small vertlcal pipe 51 carrying any air given olf by the liquid into the space above the liquid level in the container 22. l

By thus passing the liquid to be congealed the jet pipe 25.

Figs. '1 'and 8 show somewhat diagrammatically an embodiment of an ice making machine having a stationary plane freezing surface and a movable milling cutter and liquid supplying device. The freezing surface 60 is the horizontal uppermost surface of a flat hollow Acooling box 6| cooled in any appropriate manner. This box has extensions 62 serving as supports for the milling cutter 63 and the liquid supplying device 64 when these occupy positions outside the freezing surface. The milling cutter 63 and the liquid supplying device 64 as well as a container 65 feeding the same are all carried by a common slide or bracket not shown fixing their mutual distances and moved to and fro together with them. This unit is reciprocated in the longitudinal direction of the machine by means of cranks 66 and connecting rods 61. The said cranks are secured on a crank shaft 68 carrying a belt pulley 69 driven in a suitable manner. i During the working stroke, i. e. while travelling from the right to the left, the milling cutter 63 is rapidly rotated around its own axis by means of the gear wheel mechanism shown at the left end of Fig. 8. This mechanism includes a pair of pinions 10 loosely mounted on the-shaft of the milling cutter and meshing with a pair of stationary racks 1I. At the end adjacent to the crank shaft 68 the racks are provided with pivoted links 12 normally held in horizontal position by a spring 13 against a stop 14. v At the opposite end two pivoted links 15 likewise are provided which need not be provided with springs as these links are held by gravity in engagement with the extensions 62 of the freezing surface.

During the reciprocation ofthe milling cutter 63 it will alternately run .above the racks in a direction towards .the crank shaft 68 and below the racks in the opposite direction. This latter stroke constitutes the working stroke during which removal of the ice and delivery of liquid take place, whereas the return stroke is an idle stroke.

In order to ensure that liquid is only supplied to 15 when these are turned downward, whereas the sleeve valve is opened by levers 11 rigidly secured through the hollow shaft 24- as above described 75 to the counterweights and said valve when these 1 I f Y levers engage the pivotedlinksl! when beginning the working strcke; nuringtms stroke nestevalve is held open untill the'levers leave theracks 1| whereby the liquid supplyis' automatically cut' off. -ll is a screen' preventing the ,ice particlesjs from being hurled laround by the milling cutter. As stated above the liquid supplyingl device Il is fed with liquid from a container This container by means of a flexible hosev 1I is connected with a stationary 'tank Il or a liquid supply con- 1,0 duit.

During the Working stroke liquid is supplied to the freezing surface a short distance behind the revolving cutter 83. The liquid is congealed to a uniformly frozen, dry, hard ice layer from which 1 5 the ice is removed in the form of thin scales or` chips asin the embodiment shown in Figs. 1-6.

During the idle stroke of the milling cutter and liquid supplying device a pair of smooth rollersl '8| run on the upper surface of the links 15. the 2o racks 1I andthe links 12, until the milling cutter and said device arrive at the positions shown in dotted lines at the right end of Fig. '7. Then the working stroke commences.

The pinions 10 loosely mounted on the shaft '25 kof the milling cutter 63 mesh with small gears? d 82 on the shafts of which larger gears 83 are secured which in turn engage gears .Il rigidly secured to the shaft of the milling cutter. The latter shaft as well as the shafts of all these gear 30 wheels are mounted in the slide bracket referred to above, which also carries the container .65 with the liquid supplying device 6I.

It is thought that the invention and its advantages will be understood from the foregoing de- 35 scription and it is apparent that various changes rmay be made in theform, construction and var rangement of the parts `without departing from the spirit and scope of the invention or sacrificing its material advantagesthe,forms hereinbefore 4 described and illustratedin the drawings being merely preferred embodiments thereof.

l. In an ice making machine in combination,

a cooling body having a freezing-surface, means 45 for cooling said surface, means for delivering liquid to said surface, said cooling means being .capable of cooling said surface to a suiliciently low temperature to thoroughly congeal said liquid said surface, a revolvable milling cutter cooper able with said surface to remove congealed mate-" rial therefrom, said cooling body and said milling cutter being relatively movable in addition to the rotation of the latter, and means for heating said milling cutter to facilitate removal of any particles therefrom.

2. In an ice making machine in combination, a cooling body having a freezing surface, means for cooling said surface, means for delivering liquid to said surface, said cooling means being capable of cooling said surface to a sumcien'tly low temperature to thoroughly congeal said liquid to form a layer of hard dry ice on said surface. 65 a revolvable milling cutter co-operable with said surface to remove congealed material therefrom, said cooling body and said milling cutter being relatively movable in addition to the rotation of the latter, said milling cutter having a cavity, and 70 means for circulating a comparatively warm fluid through-said cavity.

3. In an ice making machine-incombination, a stationary cooling body havlnga plane lfreezing surface, means for cooling said surface, means 75 ione end thereof to `theotlie. said cooling means being capable Yof cooling` 'said surface toa sumcient'ly low temperature to thoroughly congeal" said liquid to form a layer of hard dry ice on said surface, a rvolvaizvle `milling cutter cooperable with said surface to remove congealed material therefrom in the 'form of dry-thinscale or cuttings,

and -means for bodily moving said-revolvable millving cutter along 'said piane freezing surface.

4. In an .ice making machine in combination. .a stationary bodyhaving a plane freez- .ing surface,'me'ans for cooling said surface, means Afor sraduallydelivering liquid to said surface Afrom one end thereof to the other, said cooling means being capable of cooling said surface to a suillcientlylow temperature to thoroughly con- .'geal said liquid to form av layer of hard dry ice on saidsurface, a revoivable 'milling cutter cooperable with vsaid surface to remove congealed material therefrom, and means for bodily moving saidrevolvable milling cutter `in one direction along said plane freezing surface while milling off ice therefrom and for bodily returningr said milling cutter in the opposite direction while spaced from said freezing surface.

j 5. In an ice making machine in combination, a rotatable cooling drum having an external freezing surface and an internal chamber for receiving a refrigeratin'gmedium, means for delivering liquid to said freezingsurface, a revolvable milling cutter co-operable with said freezing surface at a line where the material congealed on said freezing surface forms a thoroughly dry hard undercooled ice layer. so that the milling cutter will remove the ice in the form of dry. thin scale or cuttings, and means for heating said milling cutter to release said ice scale or cuttings.

6. In an ice making machine in combination, a rotatable cooling drum having an external freezing' surface and an internal chamber for receiving a refrigerating medium, means for delivering liquid to said freezing surface, a revolvable milling cutter co-operable with said freezing surface to cut ice therefrom in a finely divided state, said milling cutter having a cavity, and means for circulating a comparatively warm fluid through said cavity. j

7. In an ice making machine in combination, a rotatable cooling drum having an external freezing surface and an internal chamber for receiving a refrigerating medium, means for delivering liquid to said freezing surface, a revolvable milling cutter co-operable with said freezing surface to cut ice therefrom in a finely divided state, said milling cutter having a cavity, and

means for passing said liquid through said cavity vbefore the liquid is delivered to the freezing surface..

8. In an ice making machine in combination, a rotatable cooling drum having an' external -freezing surface and an internal chamber for a cooling drum rotatable about a horizontal axis and having an external freezing surface, means fori' rotating said drum in one direction, means for cooling said freezing surface. means for -de- 9 livering liquid to be congealedV to said freezing surface at a distance from the uppermost portion thereof, said cooling means being capable of causing a layer of yhard dry undercooled ice to be formed on said freezing surface, and a revolvable milling vcutter co-operable with said freezing surface to cut ice from said layer in the form of thin chips and angularly spaced more than 300 from said liquid delivering means measured from the latter in the direction of rotation of the drum.

10. In an ice making machine in combination, two co-axial cylindrical drums of different diameters forming therebetween an annular narrow cooling space, a rotatable shaft, hollow spokes at each end of the drums for carrying the same on said shaft and also forming transfer passages leading from each end of said annular cooling space to said shaft, means for circulating a refrigerating medium through said hollowl spokes and annular cooling chamber, means for supplying liquid to the outer cylindrical surface ofthe outermost of said drums, and a revolvable milling cutter co-operable with said outer-,cylindrical surface to mill on material congealed on the same.

l1. The ice making machine of claim 10, in which means for heating said milling cutter are provided for preventing milled oil.' congealed material from clossins said cutter.

' AXEL GRUHN.

REFERENCES CITED The following references are of record inv the y Number Name Date 638,577 Harris Dec. 5, 1899 670,247 Rauch Mar. 19, 1901 1,044,972 Bannister Nov, 19, 1912 1,528,043 Bennett Mar. 3, 1925 l1,931,347 Gay Oct. 17, 1933 1,963,842 Gay .s'. June 19, 1934 2,063,770 Taylor Dec. 8, 1936 2,063,771 Taylor Dec. 8, 1936 2,080,639 Taylor `May 18, 1937 2,082,439 Bazzi June 1, 1937 2,104,260 Kemp Jan. 5, 1938 2,141,462 Doering 1-,2---- Dec. 27, 1938 2,150,616 Thilenius Mar. 14, 1939 FOREIGN PATENTS Number Country Date 1,334 Great Britain Mar. 25, 1881 2,763 Great Britain Aug. 10, 1874 14,577 Great Britain July 17, 1901 569,071 Germany Jan. 30, 1933

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